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2024-09-05dma-mapping: use IOMMU DMA calls for common alloc/free page callsLeon Romanovsky
Common alloca and free pages routines are called when IOMMU DMA is used, and internally it calls to DMA ops structure which is not available for default IOMMU. This patch adds necessary if checks to call IOMMU DMA. It fixes the following crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000000d20bb000 [0000000000000040] pgd=08000000d20c1003 , p4d=08000000d20c1003 , pud=08000000d20c2003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: ipv6 hci_uart venus_core btqca v4l2_mem2mem btrtl qcom_spmi_adc5 sbs_battery btbcm qcom_vadc_common cros_ec_typec videobuf2_v4l2 leds_cros_ec cros_kbd_led_backlight cros_ec_chardev videodev elan_i2c videobuf2_common qcom_stats mc bluetooth coresight_stm stm_core ecdh_generic ecc pwrseq_core panel_edp icc_bwmon ath10k_snoc ath10k_core ath mac80211 phy_qcom_qmp_combo aux_bridge libarc4 coresight_replicator coresight_etm4x coresight_tmc coresight_funnel cfg80211 rfkill coresight qcom_wdt cbmem ramoops reed_solomon pwm_bl coreboot_table backlight crct10dif_ce CPU: 7 UID: 0 PID: 70 Comm: kworker/u32:4 Not tainted 6.11.0-rc6-next-20240903-00003-gdfc6015d0711 #660 Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT) Workqueue: events_unbound deferred_probe_work_func hub 2-1:1.0: 4 ports detected pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : dma_common_alloc_pages+0x54/0x1b4 lr : dma_common_alloc_pages+0x4c/0x1b4 sp : ffff8000807d3730 x29: ffff8000807d3730 x28: ffff02a7d312f880 x27: 0000000000000001 x26: 000000000000c000 x25: 0000000000000000 x24: 0000000000000001 x23: ffff02a7d23b6898 x22: 0000000000006cc0 x21: 000000000000c000 x20: ffff02a7858bf410 x19: fffffe0a60006000 x18: 0000000000000001 x17: 00000000000000d5 x16: 1fffe054f0bcc261 x15: 0000000000000001 x14: ffff02a7844dc680 x13: 0000000000100180 x12: dead000000000100 x11: dead000000000122 x10: 00000000001001ff x9 : ffff02a87f7b7b00 x8 : ffff02a87f7b7b00 x7 : ffff405977d6b000 x6 : ffff8000807d3310 x5 : ffff02a87f6b6398 x4 : 0000000000000001 x3 : ffff405977d6b000 x2 : ffff02a7844dc600 x1 : 0000000100000000 x0 : fffffe0a60006000 Call trace: dma_common_alloc_pages+0x54/0x1b4 __dma_alloc_pages+0x68/0x90 dma_alloc_pages+0x10/0x1c snd_dma_noncoherent_alloc+0x28/0x8c __snd_dma_alloc_pages+0x30/0x50 snd_dma_alloc_dir_pages+0x40/0x80 do_alloc_pages+0xb8/0x13c preallocate_pcm_pages+0x6c/0xf8 preallocate_pages+0x160/0x1a4 snd_pcm_set_managed_buffer_all+0x64/0xb0 lpass_platform_pcm_new+0xc0/0xe8 snd_soc_pcm_component_new+0x3c/0xc8 soc_new_pcm+0x4fc/0x668 snd_soc_bind_card+0xabc/0xbac snd_soc_register_card+0xf0/0x108 devm_snd_soc_register_card+0x4c/0xa4 sc7180_snd_platform_probe+0x180/0x224 platform_probe+0x68/0xc0 really_probe+0xbc/0x298 __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x15c __device_attach_driver+0xb8/0x134 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 deferred_probe_work_func+0x88/0xc0 process_one_work+0x14c/0x28c worker_thread+0x2cc/0x3d4 kthread+0x114/0x118 ret_from_fork+0x10/0x20 Code: f9411c19 940000c9 aa0003f3 b4000460 (f9402326) ---[ end trace 0000000000000000 ]--- Fixes: b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu") Closes: https://lore.kernel.org/all/10431dfd-ce04-4e0f-973b-c78477303c18@notapiano Reported-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> #KernelCI Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-09-04dma-mapping: clearly mark DMA ops as an architecture featureChristoph Hellwig
DMA ops are a helper for architectures and not for drivers to override the DMA implementation. Unfortunately driver authors keep ignoring this. Make the fact more clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers overriding their dma_ops depend on that. These drivers should probably be marked broken, but we can give them a bit of a grace period for that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6 Acked-by: Robin Murphy <robin.murphy@arm.com>
2024-08-29dma-mapping: don't return errors from dma_set_max_seg_sizeChristoph Hellwig
A NULL dev->dma_parms indicates either a bus that is not DMA capable or grave bug in the implementation of the bus code. There isn't much the driver can do in terms of error handling for either case, so just warn and continue as DMA operations will fail anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
2024-08-29dma-mapping: don't return errors from dma_set_seg_boundaryChristoph Hellwig
A NULL dev->dma_parms indicates either a bus that is not DMA capable or grave bug in the implementation of the bus code. There isn't much the driver can do in terms of error handling for either case, so just warn and continue as DMA operations will fail anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-08-29dma-mapping: don't return errors from dma_set_min_align_maskChristoph Hellwig
A NULL dev->dma_parms indicates either a bus that is not DMA capable or grave bug in the implementation of the bus code. There isn't much the driver can do in terms of error handling for either case, so just warn and continue as DMA operations will fail anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-08-22dma-mapping: direct calls for dma-iommuLeon Romanovsky
Directly call into dma-iommu just like we have been doing for dma-direct for a while. This avoids the indirect call overhead for IOMMU ops and removes the need to have DMA ops entirely for many common configurations. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22dma-mapping: replace zone_dma_bits by zone_dma_limitCatalin Marinas
The hardware DMA limit might not be power of 2. When RAM range starts above 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high bit can not encode this limit. Use a plain address for the DMA zone limit instead. Since the DMA zone can now potentially span beyond 4GB physical limit of DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Co-developed-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Petr Tesarik <ptesarik@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-17Merge tag 'mm-hotfixes-stable-2024-08-17-19-34' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "16 hotfixes. All except one are for MM. 10 of these are cc:stable and the others pertain to post-6.10 issues. As usual with these merges, singletons and doubletons all over the place, no identifiable-by-me theme. Please see the lovingly curated changelogs to get the skinny" * tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/migrate: fix deadlock in migrate_pages_batch() on large folios alloc_tag: mark pages reserved during CMA activation as not tagged alloc_tag: introduce clear_page_tag_ref() helper function crash: fix riscv64 crash memory reserve dead loop selftests: memfd_secret: don't build memfd_secret test on unsupported arches mm: fix endless reclaim on machines with unaccepted memory selftests/mm: compaction_test: fix off by one in check_compaction() mm/numa: no task_numa_fault() call if PMD is changed mm/numa: no task_numa_fault() call if PTE is changed mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0 mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu mm: don't account memmap per-node mm: add system wide stats items category mm: don't account memmap on failure mm/hugetlb: fix hugetlb vs. core-mm PT locking mseal: fix is_madv_discard()
2024-08-17Merge tag 'i2c-for-6.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fixes from Wolfram Sang: "I2C core fix replacing IS_ENABLED() with IS_REACHABLE() For host drivers, there are two fixes: - Tegra I2C Controller: Addresses a potential double-locking issue during probe. ACPI devices are not IRQ-safe when invoking runtime suspend and resume functions, so the irq_safe flag should not be set. - Qualcomm GENI I2C Controller: Fixes an oversight in the exit path of the runtime_resume() function, which was missed in the previous release" * tag 'i2c-for-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: tegra: Do not mark ACPI devices as irq safe i2c: Use IS_REACHABLE() for substituting empty ACPI functions i2c: qcom-geni: Add missing geni_icc_disable in geni_i2c_runtime_resume
2024-08-16Merge tag 'thermal-6.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull thermal control fix from Rafael Wysocki: "Fix a Bang-bang thermal governor issue causing it to fail to reset the state of cooling devices if they are 'on' to start with, but the thermal zone temperature is always below the corresponding trip point (Rafael Wysocki)" * tag 'thermal-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: thermal: gov_bang_bang: Use governor_data to reduce overhead thermal: gov_bang_bang: Add .manage() callback thermal: gov_bang_bang: Split bang_bang_control() thermal: gov_bang_bang: Call __thermal_cdev_update() directly
2024-08-16Merge tag 'iommu-fixes-v6.11-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux Pull iommu fixes from Joerg Roedel: - Bring back a lost return statement in io-page-fault code - Remove an unused function declaration * tag 'iommu-fixes-v6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: iommu: Remove unused declaration iommu_sva_unbind_gpasid() iommu: Restore lost return in iommu_report_device_fault()
2024-08-16Merge tag 'sound-6.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "All small fixes, mostly for usual suspects, HD-audio and USB-audio device-specific fixes / quirks. The Cirrus codec support took the update of SPI header as well. Other than that, there is a regression fix in the sanity check of ALSA timer code" * tag 'sound-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: hda/tas2781: Use correct endian conversion ALSA: usb-audio: Support Yamaha P-125 quirk entry ALSA: hda: cs35l41: Remove redundant call to hda_cs_dsp_control_remove() ALSA: hda: cs35l56: Remove redundant call to hda_cs_dsp_control_remove() ALSA: hda/tas2781: fix wrong calibrated data order ALSA: usb-audio: Add delay quirk for VIVO USB-C-XE710 HEADSET ALSA: hda/realtek: Add support for new HP G12 laptops ALSA: hda/realtek: Fix noise from speakers on Lenovo IdeaPad 3 15IAU7 ALSA: timer: Relax start tick time check for slave timer elements spi: Add empty versions of ACPI functions
2024-08-16thermal: gov_bang_bang: Use governor_data to reduce overheadRafael J. Wysocki
After running once, the for_each_trip_desc() loop in bang_bang_manage() is pure needless overhead because it is not going to make any changes unless a new cooling device has been bound to one of the trips in the thermal zone or the system is resuming from sleep. For this reason, make bang_bang_manage() set governor_data for the thermal zone and check it upfront to decide whether or not it needs to do anything. However, governor_data needs to be reset in some cases to let bang_bang_manage() know that it should walk the trips again, so add an .update_tz() callback to the governor and make the core additionally invoke it during system resume. To avoid affecting the other users of that callback unnecessarily, add a special notification reason for system resume, THERMAL_TZ_RESUME, and also pass it to __thermal_zone_device_update() called during system resume for consistency. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Kästle <peter@piie.net> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Cc: 6.10+ <stable@vger.kernel.org> # 6.10+ Link: https://patch.msgid.link/2285575.iZASKD2KPV@rjwysocki.net
2024-08-15alloc_tag: introduce clear_page_tag_ref() helper functionSuren Baghdasaryan
In several cases we are freeing pages which were not allocated using common page allocators. For such cases, in order to keep allocation accounting correct, we should clear the page tag to indicate that the page being freed is expected to not have a valid allocation tag. Introduce clear_page_tag_ref() helper function to be used for this. Link: https://lkml.kernel.org/r/20240813150758.855881-1-surenb@google.com Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty") Signed-off-by: Suren Baghdasaryan <surenb@google.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Sourav Panda <souravpanda@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [6.10] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15mm: don't account memmap per-nodePasha Tatashin
Fix invalid access to pgdat during hot-remove operation: ndctl users reported a GPF when trying to destroy a namespace: $ ndctl destroy-namespace all -r all -f Segmentation fault dmesg: Oops: general protection fault, probably for non-canonical address 0xdffffc0000005650: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: probably user-memory-access in range [0x000000000002b280-0x000000000002b287] CPU: 26 UID: 0 PID: 1868 Comm: ndctl Not tainted 6.11.0-rc1 #1 Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS 2.20.1 09/13/2023 RIP: 0010:mod_node_page_state+0x2a/0x110 cxl-test users report a GPF when trying to unload the test module: $ modrpobe -r cxl-test dmesg BUG: unable to handle page fault for address: 0000000000004200 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 1076 Comm: modprobe Tainted: G O N 6.11.0-rc1 #197 Tainted: [O]=OOT_MODULE, [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/15 RIP: 0010:mod_node_page_state+0x6/0x90 Currently, when memory is hot-plugged or hot-removed the accounting is done based on the assumption that memmap is allocated from the same node as the hot-plugged/hot-removed memory, which is not always the case. In addition, there are challenges with keeping the node id of the memory that is being remove to the time when memmap accounting is actually performed: since this is done after remove_pfn_range_from_zone(), and also after remove_memory_block_devices(). Meaning that we cannot use pgdat nor walking though memblocks to get the nid. Given all of that, account the memmap overhead system wide instead. For this we are going to be using global atomic counters, but given that memmap size is rarely modified, and normally is only modified either during early boot when there is only one CPU, or under a hotplug global mutex lock, therefore there is no need for per-cpu optimizations. Also, while we are here rename nr_memmap to nr_memmap_pages, and nr_memmap_boot to nr_memmap_boot_pages to be self explanatory that the units are in page count. [pasha.tatashin@soleen.com: address a few nits from David Hildenbrand] Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240808213437.682006-4-pasha.tatashin@soleen.com Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Closes: https://lore.kernel.org/linux-cxl/CAHj4cs9Ax1=CoJkgBGP_+sNu6-6=6v=_L-ZBZY0bVLD3wUWZQg@mail.gmail.com Reported-by: Alison Schofield <alison.schofield@intel.com> Closes: https://lore.kernel.org/linux-mm/Zq0tPd2h6alFz8XF@aschofie-mobl2/#t Tested-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Fan Ni <fan.ni@samsung.com> Cc: Joel Granados <j.granados@samsung.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zhijian <lizhijian@fujitsu.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15mm: add system wide stats items categoryPasha Tatashin
/proc/vmstat contains events and stats, events can only grow, but stats can grow and shrink. vmstat has the following: ------------------------- NR_VM_ZONE_STAT_ITEMS: per-zone stats NR_VM_NUMA_EVENT_ITEMS: per-numa events NR_VM_NODE_STAT_ITEMS: per-numa stats NR_VM_WRITEBACK_STAT_ITEMS: system-wide background-writeback and dirty-throttling tresholds. NR_VM_EVENT_ITEMS: system-wide events ------------------------- Rename NR_VM_WRITEBACK_STAT_ITEMS to NR_VM_STAT_ITEMS, to track the system-wide stats, we are going to add per-page metadata stats to this category in the next patch. Also delete unused writeback_stat_name(). Link: https://lkml.kernel.org/r/20240809191020.1142142-2-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240808213437.682006-3-pasha.tatashin@soleen.com Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Suggested-by: Yosry Ahmed <yosryahmed@google.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Joel Granados <j.granados@samsung.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zhijian <lizhijian@fujitsu.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yi Zhang <yi.zhang@redhat.com> Cc: Fan Ni <fan.ni@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15mm/hugetlb: fix hugetlb vs. core-mm PT lockingDavid Hildenbrand
We recently made GUP's common page table walking code to also walk hugetlb VMAs without most hugetlb special-casing, preparing for the future of having less hugetlb-specific page table walking code in the codebase. Turns out that we missed one page table locking detail: page table locking for hugetlb folios that are not mapped using a single PMD/PUD. Assume we have hugetlb folio that spans multiple PTEs (e.g., 64 KiB hugetlb folios on arm64 with 4 KiB base page size). GUP, as it walks the page tables, will perform a pte_offset_map_lock() to grab the PTE table lock. However, hugetlb that concurrently modifies these page tables would actually grab the mm->page_table_lock: with USE_SPLIT_PTE_PTLOCKS, the locks would differ. Something similar can happen right now with hugetlb folios that span multiple PMDs when USE_SPLIT_PMD_PTLOCKS. This issue can be reproduced [1], for example triggering: [ 3105.936100] ------------[ cut here ]------------ [ 3105.939323] WARNING: CPU: 31 PID: 2732 at mm/gup.c:142 try_grab_folio+0x11c/0x188 [ 3105.944634] Modules linked in: [...] [ 3105.974841] CPU: 31 PID: 2732 Comm: reproducer Not tainted 6.10.0-64.eln141.aarch64 #1 [ 3105.980406] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20240524-4.fc40 05/24/2024 [ 3105.986185] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 3105.991108] pc : try_grab_folio+0x11c/0x188 [ 3105.994013] lr : follow_page_pte+0xd8/0x430 [ 3105.996986] sp : ffff80008eafb8f0 [ 3105.999346] x29: ffff80008eafb900 x28: ffffffe8d481f380 x27: 00f80001207cff43 [ 3106.004414] x26: 0000000000000001 x25: 0000000000000000 x24: ffff80008eafba48 [ 3106.009520] x23: 0000ffff9372f000 x22: ffff7a54459e2000 x21: ffff7a546c1aa978 [ 3106.014529] x20: ffffffe8d481f3c0 x19: 0000000000610041 x18: 0000000000000001 [ 3106.019506] x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000000 [ 3106.024494] x14: ffffb85477fdfe08 x13: 0000ffff9372ffff x12: 0000000000000000 [ 3106.029469] x11: 1fffef4a88a96be1 x10: ffff7a54454b5f0c x9 : ffffb854771b12f0 [ 3106.034324] x8 : 0008000000000000 x7 : ffff7a546c1aa980 x6 : 0008000000000080 [ 3106.038902] x5 : 00000000001207cf x4 : 0000ffff9372f000 x3 : ffffffe8d481f000 [ 3106.043420] x2 : 0000000000610041 x1 : 0000000000000001 x0 : 0000000000000000 [ 3106.047957] Call trace: [ 3106.049522] try_grab_folio+0x11c/0x188 [ 3106.051996] follow_pmd_mask.constprop.0.isra.0+0x150/0x2e0 [ 3106.055527] follow_page_mask+0x1a0/0x2b8 [ 3106.058118] __get_user_pages+0xf0/0x348 [ 3106.060647] faultin_page_range+0xb0/0x360 [ 3106.063651] do_madvise+0x340/0x598 Let's make huge_pte_lockptr() effectively use the same PT locks as any core-mm page table walker would. Add ptep_lockptr() to obtain the PTE page table lock using a pte pointer -- unfortunately we cannot convert pte_lockptr() because virt_to_page() doesn't work with kmap'ed page tables we can have with CONFIG_HIGHPTE. Handle CONFIG_PGTABLE_LEVELS correctly by checking in reverse order, such that when e.g., CONFIG_PGTABLE_LEVELS==2 with PGDIR_SIZE==P4D_SIZE==PUD_SIZE==PMD_SIZE will work as expected. Document why that works. There is one ugly case: powerpc 8xx, whereby we have an 8 MiB hugetlb folio being mapped using two PTE page tables. While hugetlb wants to take the PMD table lock, core-mm would grab the PTE table lock of one of both PTE page tables. In such corner cases, we have to make sure that both locks match, which is (fortunately!) currently guaranteed for 8xx as it does not support SMP and consequently doesn't use split PT locks. [1] https://lore.kernel.org/all/1bbfcc7f-f222-45a5-ac44-c5a1381c596d@redhat.com/ Link: https://lkml.kernel.org/r/20240801204748.99107-1-david@redhat.com Fixes: 9cb28da54643 ("mm/gup: handle hugetlb in the generic follow_page_mask code") Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Peter Xu <peterx@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15Merge tag 'hardening-v6.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement (Thorsten Blum) - kallsyms: Clean up interaction with LTO suffixes (Song Liu) - refcount: Report UAF for refcount_sub_and_test(0) when counter==0 (Petr Pavlu) - kunit/overflow: Avoid misallocation of driver name (Ivan Orlov) * tag 'hardening-v6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kallsyms: Match symbols exactly with CONFIG_LTO_CLANG kallsyms: Do not cleanup .llvm.<hash> suffix before sorting symbols kunit/overflow: Fix UB in overflow_allocation_test gcc-plugins: randstruct: Remove GCC 4.7 or newer requirement refcount: Report UAF for refcount_sub_and_test(0) when counter==0
2024-08-14Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "s390: - Fix failure to start guests with kvm.use_gisa=0 - Panic if (un)share fails to maintain security. ARM: - Use kvfree() for the kvmalloc'd nested MMUs array - Set of fixes to address warnings in W=1 builds - Make KVM depend on assembler support for ARMv8.4 - Fix for vgic-debug interface for VMs without LPIs - Actually check ID_AA64MMFR3_EL1.S1PIE in get-reg-list selftest - Minor code / comment cleanups for configuring PAuth traps - Take kvm->arch.config_lock to prevent destruction / initialization race for a vCPU's CPUIF which may lead to a UAF x86: - Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) - Fix smatch issues - Small cleanups - Make x2APIC ID 100% readonly - Fix typo in uapi constant Generic: - Use synchronize_srcu_expedited() on irqfd shutdown" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits) KVM: SEV: uapi: fix typo in SEV_RET_INVALID_CONFIG KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) KVM: eventfd: Use synchronize_srcu_expedited() on shutdown KVM: selftests: Add a testcase to verify x2APIC is fully readonly KVM: x86: Make x2APIC ID 100% readonly KVM: x86: Use this_cpu_ptr() instead of per_cpu_ptr(smp_processor_id()) KVM: x86: hyper-v: Remove unused inline function kvm_hv_free_pa_page() KVM: SVM: Fix an error code in sev_gmem_post_populate() KVM: SVM: Fix uninitialized variable bug KVM: arm64: vgic: Hold config_lock while tearing down a CPU interface KVM: selftests: arm64: Correct feature test for S1PIE in get-reg-list KVM: arm64: Tidying up PAuth code in KVM KVM: arm64: vgic-debug: Exit the iterator properly w/o LPI KVM: arm64: Enforce dependency on an ARMv8.4-aware toolchain s390/uv: Panic for set and remove shared access UVC errors KVM: s390: fix validity interception issue when gisa is switched off docs: KVM: Fix register ID of SPSR_FIQ KVM: arm64: vgic: fix unexpected unlock sparse warnings KVM: arm64: fix kdoc warnings in W=1 builds KVM: arm64: fix override-init warnings in W=1 builds ...
2024-08-14i2c: Use IS_REACHABLE() for substituting empty ACPI functionsRichard Fitzgerald
Replace IS_ENABLED() with IS_REACHABLE() to substitute empty stubs for: i2c_acpi_get_i2c_resource() i2c_acpi_client_count() i2c_acpi_find_bus_speed() i2c_acpi_new_device_by_fwnode() i2c_adapter *i2c_acpi_find_adapter_by_handle() i2c_acpi_waive_d0_probe() commit f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions") partially fixed this conditional to depend on CONFIG_I2C, but used IS_ENABLED(), which is wrong since CONFIG_I2C is tristate. CONFIG_ACPI is boolean but let's also change it to use IS_REACHABLE() to future-proof it against becoming tristate. Somehow despite testing various combinations of CONFIG_I2C and CONFIG_ACPI we missed the combination CONFIG_I2C=m, CONFIG_ACPI=y. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Fixes: f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202408141333.gYnaitcV-lkp@intel.com/ Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2024-08-14KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX)Sean Christopherson
Disallow read-only memslots for SEV-{ES,SNP} VM types, as KVM can't directly emulate instructions for ES/SNP, and instead the guest must explicitly request emulation. Unless the guest explicitly requests emulation without accessing memory, ES/SNP relies on KVM creating an MMIO SPTE, with the subsequent #NPF being reflected into the guest as a #VC. But for read-only memslots, KVM deliberately doesn't create MMIO SPTEs, because except for ES/SNP, doing so requires setting reserved bits in the SPTE, i.e. the SPTE can't be readable while also generating a #VC on writes. Because KVM never creates MMIO SPTEs and jumps directly to emulation, the guest never gets a #VC. And since KVM simply resumes the guest if ES/SNP guests trigger emulation, KVM effectively puts the vCPU into an infinite #NPF loop if the vCPU attempts to write read-only memory. Disallow read-only memory for all VMs with protected state, i.e. for upcoming TDX VMs as well as ES/SNP VMs. For TDX, it's actually possible to support read-only memory, as TDX uses EPT Violation #VE to reflect the fault into the guest, e.g. KVM could configure read-only SPTEs with RX protections and SUPPRESS_VE=0. But there is no strong use case for supporting read-only memslots on TDX, e.g. the main historical usage is to emulate option ROMs, but TDX disallows executing from shared memory. And if someone comes along with a legitimate, strong use case, the restriction can always be lifted for TDX. Don't bother trying to retroactively apply the restriction to SEV-ES VMs that are created as type KVM_X86_DEFAULT_VM. Read-only memslots can't possibly work for SEV-ES, i.e. disallowing such memslots is really just means reporting an error to userspace instead of silently hanging vCPUs. Trying to deal with the ordering between KVM_SEV_INIT and memslot creation isn't worth the marginal benefit it would provide userspace. Fixes: 26c44aa9e076 ("KVM: SEV: define VM types for SEV and SEV-ES") Fixes: 1dfe571c12cf ("KVM: SEV: Add initial SEV-SNP support") Cc: Peter Gonda <pgonda@google.com> Cc: Michael Roth <michael.roth@amd.com> Cc: Vishal Annapurve <vannapurve@google.com> Cc: Ackerly Tng <ackerleytng@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240809190319.1710470-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-08-14Merge tag 'vfs-6.11-rc4.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: "VFS: - Fix the name of file lease slab cache. When file leases were split out of file locks the name of the file lock slab cache was used for the file leases slab cache as well. - Fix a type in take_fd() helper. - Fix infinite directory iteration for stable offsets in tmpfs. - When the icache is pruned all reclaimable inodes are marked with I_FREEING and other processes that try to lookup such inodes will block. But some filesystems like ext4 can trigger lookups in their inode evict callback causing deadlocks. Ext4 does such lookups if the ea_inode feature is used whereby a separate inode may be used to store xattrs. Introduce I_LRU_ISOLATING which pins the inode while its pages are reclaimed. This avoids inode deletion during inode_lru_isolate() avoiding the deadlock and evict is made to wait until I_LRU_ISOLATING is done. netfs: - Fault in smaller chunks for non-large folio mappings for filesystems that haven't been converted to large folios yet. - Fix the CONFIG_NETFS_DEBUG config option. The config option was renamed a short while ago and that introduced two minor issues. First, it depended on CONFIG_NETFS whereas it wants to depend on CONFIG_NETFS_SUPPORT. The former doesn't exist, while the latter does. Second, the documentation for the config option wasn't fixed up. - Revert the removal of the PG_private_2 writeback flag as ceph is using it and fix how that flag is handled in netfs. - Fix DIO reads on 9p. A program watching a file on a 9p mount wouldn't see any changes in the size of the file being exported by the server if the file was changed directly in the source filesystem. Fix this by attempting to read the full size specified when a DIO read is requested. - Fix a NULL pointer dereference bug due to a data race where a cachefiles cookies was retired even though it was still in use. Check the cookie's n_accesses counter before discarding it. nsfs: - Fix ioctl declaration for NS_GET_MNTNS_ID from _IO() to _IOR() as the kernel is writing to userspace. pidfs: - Prevent the creation of pidfds for kthreads until we have a use-case for it and we know the semantics we want. It also confuses userspace why they can get pidfds for kthreads. squashfs: - Fix an unitialized value bug reported by KMSAN caused by a corrupted symbolic link size read from disk. Check that the symbolic link size is not larger than expected" * tag 'vfs-6.11-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: Squashfs: sanity check symbolic link size 9p: Fix DIO read through netfs vfs: Don't evict inode under the inode lru traversing context netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags netfs, ceph: Revert "netfs: Remove deprecated use of PG_private_2 as a second writeback flag" file: fix typo in take_fd() comment pidfd: prevent creation of pidfds for kthreads netfs: clean up after renaming FSCACHE_DEBUG config libfs: fix infinite directory reads for offset dir nsfs: fix ioctl declaration fs/netfs/fscache_cookie: add missing "n_accesses" check filelock: fix name of file_lease slab cache netfs: Fault in smaller chunks for non-large folio mappings
2024-08-13vfs: Don't evict inode under the inode lru traversing contextZhihao Cheng
The inode reclaiming process(See function prune_icache_sb) collects all reclaimable inodes and mark them with I_FREEING flag at first, at that time, other processes will be stuck if they try getting these inodes (See function find_inode_fast), then the reclaiming process destroy the inodes by function dispose_list(). Some filesystems(eg. ext4 with ea_inode feature, ubifs with xattr) may do inode lookup in the inode evicting callback function, if the inode lookup is operated under the inode lru traversing context, deadlock problems may happen. Case 1: In function ext4_evict_inode(), the ea inode lookup could happen if ea_inode feature is enabled, the lookup process will be stuck under the evicting context like this: 1. File A has inode i_reg and an ea inode i_ea 2. getfattr(A, xattr_buf) // i_ea is added into lru // lru->i_ea 3. Then, following three processes running like this: PA PB echo 2 > /proc/sys/vm/drop_caches shrink_slab prune_dcache_sb // i_reg is added into lru, lru->i_ea->i_reg prune_icache_sb list_lru_walk_one inode_lru_isolate i_ea->i_state |= I_FREEING // set inode state inode_lru_isolate __iget(i_reg) spin_unlock(&i_reg->i_lock) spin_unlock(lru_lock) rm file A i_reg->nlink = 0 iput(i_reg) // i_reg->nlink is 0, do evict ext4_evict_inode ext4_xattr_delete_inode ext4_xattr_inode_dec_ref_all ext4_xattr_inode_iget ext4_iget(i_ea->i_ino) iget_locked find_inode_fast __wait_on_freeing_inode(i_ea) ----→ AA deadlock dispose_list // cannot be executed by prune_icache_sb wake_up_bit(&i_ea->i_state) Case 2: In deleted inode writing function ubifs_jnl_write_inode(), file deleting process holds BASEHD's wbuf->io_mutex while getting the xattr inode, which could race with inode reclaiming process(The reclaiming process could try locking BASEHD's wbuf->io_mutex in inode evicting function), then an ABBA deadlock problem would happen as following: 1. File A has inode ia and a xattr(with inode ixa), regular file B has inode ib and a xattr. 2. getfattr(A, xattr_buf) // ixa is added into lru // lru->ixa 3. Then, following three processes running like this: PA PB PC echo 2 > /proc/sys/vm/drop_caches shrink_slab prune_dcache_sb // ib and ia are added into lru, lru->ixa->ib->ia prune_icache_sb list_lru_walk_one inode_lru_isolate ixa->i_state |= I_FREEING // set inode state inode_lru_isolate __iget(ib) spin_unlock(&ib->i_lock) spin_unlock(lru_lock) rm file B ib->nlink = 0 rm file A iput(ia) ubifs_evict_inode(ia) ubifs_jnl_delete_inode(ia) ubifs_jnl_write_inode(ia) make_reservation(BASEHD) // Lock wbuf->io_mutex ubifs_iget(ixa->i_ino) iget_locked find_inode_fast __wait_on_freeing_inode(ixa) | iput(ib) // ib->nlink is 0, do evict | ubifs_evict_inode | ubifs_jnl_delete_inode(ib) ↓ ubifs_jnl_write_inode ABBA deadlock ←-----make_reservation(BASEHD) dispose_list // cannot be executed by prune_icache_sb wake_up_bit(&ixa->i_state) Fix the possible deadlock by using new inode state flag I_LRU_ISOLATING to pin the inode in memory while inode_lru_isolate() reclaims its pages instead of using ordinary inode reference. This way inode deletion cannot be triggered from inode_lru_isolate() thus avoiding the deadlock. evict() is made to wait for I_LRU_ISOLATING to be cleared before proceeding with inode cleanup. Link: https://lore.kernel.org/all/37c29c42-7685-d1f0-067d-63582ffac405@huaweicloud.com/ Link: https://bugzilla.kernel.org/show_bug.cgi?id=219022 Fixes: e50e5129f384 ("ext4: xattr-in-inode support") Fixes: 7959cf3a7506 ("ubifs: journal: Handle xattrs like files") Cc: stable@vger.kernel.org Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Link: https://lore.kernel.org/r/20240809031628.1069873-1-chengzhihao@huaweicloud.com Reviewed-by: Jan Kara <jack@suse.cz> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-13iommu: Remove unused declaration iommu_sva_unbind_gpasid()Yue Haibing
Commit 0c9f17877891 ("iommu: Remove guest pasid related interfaces and definitions") removed the implementation but leave declaration. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20240808140619.2498535-1-yuehaibing@huawei.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-08-12bpf: Fix updating attached freplace prog in prog_array mapLeon Hwang
The commit f7866c358733 ("bpf: Fix null pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT") fixed a NULL pointer dereference panic, but didn't fix the issue that fails to update attached freplace prog to prog_array map. Since commit 1c123c567fb1 ("bpf: Resolve fext program type when checking map compatibility"), freplace prog and its target prog are able to tail call each other. And the commit 3aac1ead5eb6 ("bpf: Move prog->aux->linked_prog and trampoline into bpf_link on attach") sets prog->aux->dst_prog as NULL after attaching freplace prog to its target prog. After loading freplace the prog_array's owner type is BPF_PROG_TYPE_SCHED_CLS. Then, after attaching freplace its prog->aux->dst_prog is NULL. Then, while updating freplace in prog_array the bpf_prog_map_compatible() incorrectly returns false because resolve_prog_type() returns BPF_PROG_TYPE_EXT instead of BPF_PROG_TYPE_SCHED_CLS. After this patch the resolve_prog_type() returns BPF_PROG_TYPE_SCHED_CLS and update to prog_array can succeed. Fixes: f7866c358733 ("bpf: Fix null pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT") Cc: Toke Høiland-Jørgensen <toke@redhat.com> Cc: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20240728114612.48486-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-12netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flagsDavid Howells
The NETFS_RREQ_USE_PGPRIV2 and NETFS_RREQ_WRITE_TO_CACHE flags aren't used correctly. The problem is that we try to set them up in the request initialisation, but we the cache may be in the process of setting up still, and so the state may not be correct. Further, we secondarily sample the cache state and make contradictory decisions later. The issue arises because we set up the cache resources, which allows the cache's ->prepare_read() to switch on NETFS_SREQ_COPY_TO_CACHE - which triggers cache writing even if we didn't set the flags when allocating. Fix this in the following way: (1) Drop NETFS_ICTX_USE_PGPRIV2 and instead set NETFS_RREQ_USE_PGPRIV2 in ->init_request() rather than trying to juggle that in netfs_alloc_request(). (2) Repurpose NETFS_RREQ_USE_PGPRIV2 to merely indicate that if caching is to be done, then PG_private_2 is to be used rather than only setting it if we decide to cache and then having netfs_rreq_unlock_folios() set the non-PG_private_2 writeback-to-cache if it wasn't set. (3) Split netfs_rreq_unlock_folios() into two functions, one of which contains the deprecated code for using PG_private_2 to avoid accidentally doing the writeback path - and always use it if USE_PGPRIV2 is set. (4) As NETFS_ICTX_USE_PGPRIV2 is removed, make netfs_write_begin() always wait for PG_private_2. This function is deprecated and only used by ceph anyway, and so label it so. (5) Drop the NETFS_RREQ_WRITE_TO_CACHE flag and use fscache_operation_valid() on the cache_resources instead. This has the advantage of picking up the result of netfs_begin_cache_read() and fscache_begin_write_operation() - which are called after the object is initialised and will wait for the cache to come to a usable state. Just reverting ae678317b95e[1] isn't a sufficient fix, so this need to be applied on top of that. Without this as well, things like: rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { and: WARNING: CPU: 13 PID: 3621 at fs/ceph/caps.c:3386 may happen, along with some UAFs due to PG_private_2 not getting used to wait on writeback completion. Fixes: 2ff1e97587f4 ("netfs: Replace PG_fscache by setting folio->private and marking dirty") Reported-by: Max Kellermann <max.kellermann@ionos.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Ilya Dryomov <idryomov@gmail.com> cc: Xiubo Li <xiubli@redhat.com> cc: Hristo Venev <hristo@venev.name> cc: Jeff Layton <jlayton@kernel.org> cc: Matthew Wilcox <willy@infradead.org> cc: ceph-devel@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/3575457.1722355300@warthog.procyon.org.uk/ [1] Link: https://lore.kernel.org/r/1173209.1723152682@warthog.procyon.org.uk Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-12file: fix typo in take_fd() commentMathias Krause
The explanatory comment above take_fd() contains a typo, fix that to not confuse readers. Signed-off-by: Mathias Krause <minipli@grsecurity.net> Link: https://lore.kernel.org/r/20240809135035.748109-1-minipli@grsecurity.net Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-12Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull fd bitmap fix from Al Viro: "Fix bitmap corruption on close_range() by cleaning up copy_fd_bitmaps()" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE
2024-08-12Merge tag 'spi-acpi-lookup-dummy' of ↵Takashi Iwai
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into topic/cirrus-hp-g12 spi: Add empty versions of ACPI lookup functions A patch from Richard Fitzgerald adding dummy versions of the ACPI lookup functions for SPI: Provide empty versions of acpi_spi_count_resources(), acpi_spi_device_alloc() and acpi_spi_find_controller_by_adev() if the real functions are not being built. This commit fixes two problems with the original definitions: 1) There wasn't an empty version of these functions 2) The #if only depended on CONFIG_ACPI. But the functions are implemented in the core spi.c so CONFIG_SPI_MASTER must also be enabled for the real functions to exist.
2024-08-10Merge tag 'i2c-for-6.11-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fixes from Wolfram Sang: - Two fixes for SMBusAlert handling in the I2C core: one to avoid an endless loop when scanning for handlers and one to make sure handlers are always called even if HW has broken behaviour - I2C header build fix for when ACPI is enabled but I2C isn't - The testunit gets a rename in the code to match the documentation - Two fixes for the Qualcomm GENI I2C controller are cleaning up the error exit patch in the runtime_resume() function. The first is disabling the clock, the second disables the icc on the way out * tag 'i2c-for-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: testunit: match HostNotify test name with docs i2c: qcom-geni: Add missing geni_icc_disable in geni_i2c_runtime_resume i2c: qcom-geni: Add missing clk_disable_unprepare in geni_i2c_runtime_resume i2c: Fix conditional for substituting empty ACPI functions i2c: smbus: Send alert notifications to all devices if source not found i2c: smbus: Improve handling of stuck alerts
2024-08-09Merge tag 'bitmap-6.11-rc' of https://github.com/norov/linuxLinus Torvalds
Pull cpumask fix from Yury Norov: "Fix for cpumask merge" [ Mea culpa, this was my mismerge due to too much cut-and-paste - Linus ] * tag 'bitmap-6.11-rc' of https://github.com/norov/linux: cpumask: Fix crash on updating CPU enabled mask
2024-08-09Merge tag 'probes-fixes-v6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull kprobe fixes from Masami Hiramatsu: - Fix misusing str_has_prefix() parameter order to check symbol prefix correctly - bpf: remove unused declaring of bpf_kprobe_override * tag 'probes-fixes-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: kprobes: Fix to check symbol prefixes correctly bpf: kprobe: remove unused declaring of bpf_kprobe_override
2024-08-09Merge tag 'i2c-host-fixes-6.11-rc3' of ↵Wolfram Sang
git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-current Two fixes on the Qualcomm GENI I2C controller are cleaning up the error exit patch in the runtime_resume() function. The first is disabling the clock, the second disables the icc on the way out.
2024-08-08Merge tag 'net-6.11-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bluetooth. Current release - regressions: - eth: bnxt_en: fix memory out-of-bounds in bnxt_fill_hw_rss_tbl() on older chips Current release - new code bugs: - ethtool: fix off-by-one error / kdoc contradicting the code for max RSS context IDs - Bluetooth: hci_qca: - QCA6390: fix support on non-DT platforms - QCA6390: don't call pwrseq_power_off() twice - fix a NULL-pointer derefence at shutdown - eth: ice: fix incorrect assigns of FEC counters Previous releases - regressions: - mptcp: fix handling endpoints with both 'signal' and 'subflow' flags set - virtio-net: fix changing ring count when vq IRQ coalescing not supported - eth: gve: fix use of netif_carrier_ok() during reconfig / reset Previous releases - always broken: - eth: idpf: fix bugs in queue re-allocation on reconfig / reset - ethtool: fix context creation with no parameters Misc: - linkwatch: use system_unbound_wq to ease RTNL contention" * tag 'net-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (41 commits) net: dsa: microchip: disable EEE for KSZ8567/KSZ9567/KSZ9896/KSZ9897. ethtool: Fix context creation with no parameters net: ethtool: fix off-by-one error in max RSS context IDs net: pse-pd: tps23881: include missing bitfield.h header net: fec: Stop PPS on driver remove net: bcmgenet: Properly overlay PHY and MAC Wake-on-LAN capabilities l2tp: fix lockdep splat net: stmmac: dwmac4: fix PCS duplex mode decode idpf: fix UAFs when destroying the queues idpf: fix memleak in vport interrupt configuration idpf: fix memory leaks and crashes while performing a soft reset bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl() net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register() net/smc: add the max value of fallback reason count Bluetooth: hci_sync: avoid dup filtering when passive scanning with adv monitor Bluetooth: l2cap: always unlock channel in l2cap_conless_channel() Bluetooth: hci_qca: fix a NULL-pointer derefence at shutdown Bluetooth: hci_qca: fix QCA6390 support on non-DT platforms Bluetooth: hci_qca: don't call pwrseq_power_off() twice for QCA6390 ice: Fix incorrect assigns of FEC counts ...
2024-08-08cpumask: Fix crash on updating CPU enabled maskGavin Shan
The CPU enabled mask instead of the CPU possible mask should be used by set_cpu_enabled(). Otherwise, we run into crash due to write to the read-only CPU possible mask when vCPU is hot added on ARM64. (qemu) device_add host-arm-cpu,id=cpu1,socket-id=1 Unable to handle kernel write to read-only memory at virtual address ffff800080fa7190 : Call trace: register_cpu+0x1a4/0x2e8 arch_register_cpu+0x84/0xd8 acpi_processor_add+0x480/0x5b0 acpi_bus_attach+0x1c4/0x300 acpi_dev_for_one_check+0x3c/0x50 device_for_each_child+0x68/0xc8 acpi_dev_for_each_child+0x48/0x80 acpi_bus_attach+0x84/0x300 acpi_bus_scan+0x74/0x220 acpi_scan_rescan_bus+0x54/0x88 acpi_device_hotplug+0x208/0x478 acpi_hotplug_work_fn+0x2c/0x50 process_one_work+0x15c/0x3c0 worker_thread+0x2ec/0x400 kthread+0x120/0x130 ret_from_fork+0x10/0x20 Fix it by passing the CPU enabled mask instead of the CPU possible mask to set_cpu_enabled(). Fixes: 51c4767503d5 ("Merge tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux") Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
2024-08-08net: ethtool: fix off-by-one error in max RSS context IDsEdward Cree
Both ethtool_ops.rxfh_max_context_id and the default value used when it's not specified are supposed to be exclusive maxima (the former is documented as such; the latter, U32_MAX, cannot be used as an ID since it equals ETH_RXFH_CONTEXT_ALLOC), but xa_alloc() expects an inclusive maximum. Subtract one from 'limit' to produce an inclusive maximum, and pass that to xa_alloc(). Increase bnxt's max by one to prevent a (very minor) regression, as BNXT_MAX_ETH_RSS_CTX is an inclusive max. This is safe since bnxt is not actually hard-limited; BNXT_MAX_ETH_RSS_CTX is just a leftover from old driver code that managed context IDs itself. Rename rxfh_max_context_id to rxfh_max_num_contexts to make its semantics (hopefully) more obvious. Fixes: 847a8ab18676 ("net: ethtool: let the core choose RSS context IDs") Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Link: https://patch.msgid.link/5a2d11a599aa5b0cc6141072c01accfb7758650c.1723045898.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-07ring-buffer: Remove unused function ring_buffer_nr_pages()Jianhui Zhou
Because ring_buffer_nr_pages() is not an inline function and user accesses buffer->buffers[cpu]->nr_pages directly, the function ring_buffer_nr_pages is removed. Signed-off-by: Jianhui Zhou <912460177@qq.com> Link: https://lore.kernel.org/tencent_F4A7E9AB337F44E0F4B858D07D19EF460708@qq.com Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07tracing: Use refcount for trace_event_file reference counterSteven Rostedt
Instead of using an atomic counter for the trace_event_file reference counter, use the refcount interface. It has various checks to make sure the reference counting is correct, and will warn if it detects an error (like refcount_inc() on '0'). Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240726144208.687cce24@rorschach.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-05fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHAREAl Viro
copy_fd_bitmaps(new, old, count) is expected to copy the first count/BITS_PER_LONG bits from old->full_fds_bits[] and fill the rest with zeroes. What it does is copying enough words (BITS_TO_LONGS(count/BITS_PER_LONG)), then memsets the rest. That works fine, *if* all bits past the cutoff point are clear. Otherwise we are risking garbage from the last word we'd copied. For most of the callers that is true - expand_fdtable() has count equal to old->max_fds, so there's no open descriptors past count, let alone fully occupied words in ->open_fds[], which is what bits in ->full_fds_bits[] correspond to. The other caller (dup_fd()) passes sane_fdtable_size(old_fdt, max_fds), which is the smallest multiple of BITS_PER_LONG that covers all opened descriptors below max_fds. In the common case (copying on fork()) max_fds is ~0U, so all opened descriptors will be below it and we are fine, by the same reasons why the call in expand_fdtable() is safe. Unfortunately, there is a case where max_fds is less than that and where we might, indeed, end up with junk in ->full_fds_bits[] - close_range(from, to, CLOSE_RANGE_UNSHARE) with * descriptor table being currently shared * 'to' being above the current capacity of descriptor table * 'from' being just under some chunk of opened descriptors. In that case we end up with observably wrong behaviour - e.g. spawn a child with CLONE_FILES, get all descriptors in range 0..127 open, then close_range(64, ~0U, CLOSE_RANGE_UNSHARE) and watch dup(0) ending up with descriptor #128, despite #64 being observably not open. The minimally invasive fix would be to deal with that in dup_fd(). If this proves to add measurable overhead, we can go that way, but let's try to fix copy_fd_bitmaps() first. * new helper: bitmap_copy_and_expand(to, from, bits_to_copy, size). * make copy_fd_bitmaps() take the bitmap size in words, rather than bits; it's 'count' argument is always a multiple of BITS_PER_LONG, so we are not losing any information, and that way we can use the same helper for all three bitmaps - compiler will see that count is a multiple of BITS_PER_LONG for the large ones, so it'll generate plain memcpy()+memset(). Reproducer added to tools/testing/selftests/core/close_range_test.c Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-08-05refcount: Report UAF for refcount_sub_and_test(0) when counter==0Petr Pavlu
When a reference counter is at zero and refcount_sub_and_test() is invoked to subtract zero, the function accepts this request without any warning and returns true. This behavior does not seem ideal because the counter being already at zero indicates a use-after-free. Furthermore, returning true by refcount_sub_and_test() in this case potentially results in a double-free done by its caller. Modify the underlying function __refcount_sub_and_test() to warn about this case as a use-after-free and have it return false to avoid the potential double-free. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240717130023.5675-1-petr.pavlu@suse.com Signed-off-by: Kees Cook <kees@kernel.org>
2024-08-05bpf: kprobe: remove unused declaring of bpf_kprobe_overrideMenglong Dong
After the commit 66665ad2f102 ("tracing/kprobe: bpf: Compare instruction pointer with original one"), "bpf_kprobe_override" is not used anywhere anymore, and we can remove it now. Link: https://lore.kernel.org/all/20240710085939.11520-1-dongml2@chinatelecom.cn/ Fixes: 66665ad2f102 ("tracing/kprobe: bpf: Compare instruction pointer with original one") Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-08-04profiling: remove profile=sleep supportTetsuo Handa
The kernel sleep profile is no longer working due to a recursive locking bug introduced by commit 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Booting with the 'profile=sleep' kernel command line option added or executing # echo -n sleep > /sys/kernel/profiling after boot causes the system to lock up. Lockdep reports kthreadd/3 is trying to acquire lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70 but task is already holding lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370 with the call trace being lock_acquire+0xc8/0x2f0 get_wchan+0x32/0x70 __update_stats_enqueue_sleeper+0x151/0x430 enqueue_entity+0x4b0/0x520 enqueue_task_fair+0x92/0x6b0 ttwu_do_activate+0x73/0x140 try_to_wake_up+0x213/0x370 swake_up_locked+0x20/0x50 complete+0x2f/0x40 kthread+0xfb/0x180 However, since nobody noticed this regression for more than two years, let's remove 'profile=sleep' support based on the assumption that nobody needs this functionality. Fixes: 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-04i2c: Fix conditional for substituting empty ACPI functionsRichard Fitzgerald
Add IS_ENABLED(CONFIG_I2C) to the conditional around a bunch of ACPI functions. The conditional around these functions depended only on CONFIG_ACPI. But the functions are implemented in I2C core, so are only present if CONFIG_I2C is enabled. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2024-08-02spi: Add empty versions of ACPI functionsRichard Fitzgerald
Provide empty versions of acpi_spi_count_resources(), acpi_spi_device_alloc() and acpi_spi_find_controller_by_adev() if the real functions are not being built. This commit fixes two problems with the original definitions: 1) There wasn't an empty version of these functions 2) The #if only depended on CONFIG_ACPI. But the functions are implemented in the core spi.c so CONFIG_SPI_MASTER must also be enabled for the real functions to exist. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Link: https://patch.msgid.link/20240802152215.20831-2-rf@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "The bulk of the changes here is a largish change to guest_memfd, delaying the clearing and encryption of guest-private pages until they are actually added to guest page tables. This started as "let's make it impossible to misuse the API" for SEV-SNP; but then it ballooned a bit. The new logic is generally simpler and more ready for hugepage support in guest_memfd. Summary: - fix latent bug in how usage of large pages is determined for confidential VMs - fix "underline too short" in docs - eliminate log spam from limited APIC timer periods - disallow pre-faulting of memory before SEV-SNP VMs are initialized - delay clearing and encrypting private memory until it is added to guest page tables - this change also enables another small cleanup: the checks in SNP_LAUNCH_UPDATE that limit it to non-populated, private pages can now be moved in the common kvm_gmem_populate() function - fix compilation error that the RISC-V merge introduced in selftests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86/mmu: fix determination of max NPT mapping level for private pages KVM: riscv: selftests: Fix compile error KVM: guest_memfd: abstract how prepared folios are recorded KVM: guest_memfd: let kvm_gmem_populate() operate only on private gfns KVM: extend kvm_range_has_memory_attributes() to check subset of attributes KVM: cleanup and add shortcuts to kvm_range_has_memory_attributes() KVM: guest_memfd: move check for already-populated page to common code KVM: remove kvm_arch_gmem_prepare_needed() KVM: guest_memfd: make kvm_gmem_prepare_folio() operate on a single struct kvm KVM: guest_memfd: delay kvm_gmem_prepare_folio() until the memory is passed to the guest KVM: guest_memfd: return locked folio from __kvm_gmem_get_pfn KVM: rename CONFIG_HAVE_KVM_GMEM_* to CONFIG_HAVE_KVM_ARCH_GMEM_* KVM: guest_memfd: do not go through struct page KVM: guest_memfd: delay folio_mark_uptodate() until after successful preparation KVM: guest_memfd: return folio from __kvm_gmem_get_pfn() KVM: x86: disallow pre-fault for SNP VMs before initialization KVM: Documentation: Fix title underline too short warning KVM: x86: Eliminate log spam from limited APIC timer periods
2024-08-02Merge branch 'kvm-fixes' into HEADPaolo Bonzini
* fix latent bug in how usage of large pages is determined for confidential VMs * fix "underline too short" in docs * eliminate log spam from limited APIC timer periods * disallow pre-faulting of memory before SEV-SNP VMs are initialized * delay clearing and encrypting private memory until it is added to guest page tables * this change also enables another small cleanup: the checks in SNP_LAUNCH_UPDATE that limit it to non-populated, private pages can now be moved in the common kvm_gmem_populate() function
2024-08-02Merge tag 'riscv-for-linus-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix to avoid dropping some of the internal pseudo-extensions, which breaks *envcfg dependency parsing - The kernel entry address is now aligned in purgatory, which avoids a misaligned load that can lead to crash on systems that don't support misaligned accesses early in boot - The FW_SFENCE_VMA_RECEIVED perf event was duplicated in a handful of perf JSON configurations, one of them been updated to FW_SFENCE_VMA_ASID_SENT - The starfive cache driver is now restricted to 64-bit systems, as it isn't 32-bit clean - A fix for to avoid aliasing legacy-mode perf counters with software perf counters - VM_FAULT_SIGSEGV is now handled in the page fault code - A fix for stalls during CPU hotplug due to IPIs being disabled - A fix for memblock bounds checking. This manifests as a crash on systems with discontinuous memory maps that have regions that don't fit in the linear map * tag 'riscv-for-linus-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix linear mapping checks for non-contiguous memory regions RISC-V: Enable the IPI before workqueue_online_cpu() riscv/mm: Add handling for VM_FAULT_SIGSEGV in mm_fault_error() perf: riscv: Fix selecting counters in legacy mode cache: StarFive: Require a 64-bit system perf arch events: Fix duplicate RISC-V SBI firmware event name riscv/purgatory: align riscv_kernel_entry riscv: cpufeature: Do not drop Linux-internal extensions
2024-08-01Merge tag 'net-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from wireless, bleutooth, BPF and netfilter. Current release - regressions: - core: drop bad gso csum_start and offset in virtio_net_hdr - wifi: mt76: fix null pointer access in mt792x_mac_link_bss_remove - eth: tun: add missing bpf_net_ctx_clear() in do_xdp_generic() - phy: aquantia: only poll GLOBAL_CFG regs on aqr113, aqr113c and aqr115c Current release - new code bugs: - smc: prevent UAF in inet_create() - bluetooth: btmtk: fix kernel crash when entering btmtk_usb_suspend - eth: bnxt: reject unsupported hash functions Previous releases - regressions: - sched: act_ct: take care of padding in struct zones_ht_key - netfilter: fix null-ptr-deref in iptable_nat_table_init(). - tcp: adjust clamping window for applications specifying SO_RCVBUF Previous releases - always broken: - ethtool: rss: small fixes to spec and GET - mptcp: - fix signal endpoint re-add - pm: fix backup support in signal endpoints - wifi: ath12k: fix soft lockup on suspend - eth: bnxt_en: fix RSS logic in __bnxt_reserve_rings() - eth: ice: fix AF_XDP ZC timeout and concurrency issues - eth: mlx5: - fix missing lock on sync reset reload - fix error handling in irq_pool_request_irq" * tag 'net-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (76 commits) mptcp: fix duplicate data handling mptcp: fix bad RCVPRUNED mib accounting ipv6: fix ndisc_is_useropt() handling for PIO igc: Fix double reset adapter triggered from a single taprio cmd net: MAINTAINERS: Demote Qualcomm IPA to "maintained" net: wan: fsl_qmc_hdlc: Discard received CRC net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex net/mlx5e: Add a check for the return value from mlx5_port_set_eth_ptys net/mlx5e: Fix CT entry update leaks of modify header context net/mlx5e: Require mlx5 tc classifier action support for IPsec prio capability net/mlx5: Fix missing lock on sync reset reload net/mlx5: Lag, don't use the hardcoded value of the first port net/mlx5: DR, Fix 'stack guard page was hit' error in dr_rule net/mlx5: Fix error handling in irq_pool_request_irq net/mlx5: Always drain health in shutdown callback net: Add skbuff.h to MAINTAINERS r8169: don't increment tx_dropped in case of NETDEV_TX_BUSY netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init(). netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init(). net: drop bad gso csum_start and offset in virtio_net_hdr ...
2024-08-01RISC-V: Enable the IPI before workqueue_online_cpu()Nick Hu
Sometimes the hotplug cpu stalls at the arch_cpu_idle() for a while after workqueue_online_cpu(). When cpu stalls at the idle loop, the reschedule IPI is pending. However the enable bit is not enabled yet so the cpu stalls at WFI until watchdog timeout. Therefore enable the IPI before the workqueue_online_cpu() to fix the issue. Fixes: 63c5484e7495 ("workqueue: Add multiple affinity scopes and interface to select them") Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20240717031714.1946036-1-nick.hu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-31minmax: fix up min3() and max3() tooLinus Torvalds
David Laight pointed out that we should deal with the min3() and max3() mess too, which still does excessive expansion. And our current macros are actually rather broken. In particular, the macros did this: #define min3(x, y, z) min((typeof(x))min(x, y), z) #define max3(x, y, z) max((typeof(x))max(x, y), z) and that not only is a nested expansion of possibly very complex arguments with all that involves, the typing with that "typeof()" cast is completely wrong. For example, imagine what happens in max3() if 'x' happens to be a 'unsigned char', but 'y' and 'z' are 'unsigned long'. The types are compatible, and there's no warning - but the result is just random garbage. No, I don't think we've ever hit that issue in practice, but since we now have sane infrastructure for doing this right, let's just use it. It fixes any excessive expansion, and also avoids these kinds of broken type issues. Requested-by: David Laight <David.Laight@aculab.com> Acked-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>